In recent years, there has been increased demand for a charging/discharging system that supplies electric power from a storage battery mounted on an electric vehicle (EV) to an electric appliance, which is a domestic load, and charges the storage battery mounted on the EV with electric power supplied from a commercial system. When the conventional charging/discharging system charges the storage battery mounted on the EV with the electric power supplied from the commercial system, an EV power conditioner (electric vehicle power conditioning system: EV-PCS) provided as residential equipment converts AC power into DC power, and the DC power is supplied to the EV. When the charging/discharging system supplies electric power stored in the storage battery mounted on the EV to the domestic load, the EV-PCS converts the DC power output from the storage battery mounted on the EV into AC power, and the AC power is supplied to the domestic load.
On the other hand, a cable that interconnects the storage battery mounted on the EV and a power converting device for charging/discharging the storage battery requires protecting means for protecting the cable when an excessively large electric current flows. A current interrupting device disclosed in Patent Literature 1 includes an electric wire connected to a battery, a fuse, which is cable protecting means disposed on the electric wire, and a contactor that cuts off an electric current flowing to the electric wire.